Server freezes and drops clients

The server freezes up and drops everyone on the server at the time, including the server missing from the server list whenever I join the game.

I run this server on my LAN (on a different machine from what I game on), which I think is the case.

Fixes? Workarounds?

Just making sure one thing, this is not a gmod server running in wine?

Yes, it’s running on a Windows system.